diff --git a/Objects/private/compiler/function.cpp b/Objects/private/compiler/function.cpp
index ce7e815..7b26b8d 100644
--- a/Objects/private/compiler/function.cpp
+++ b/Objects/private/compiler/function.cpp
@@ -527,6 +527,7 @@ void obj::BCgen::deinit() {
 	ASSERT(sParger);
 	if (sParger) {
 		delete sParger;
+		sParger = nullptr;
 	}
 }
 
diff --git a/Objects/private/core/module.cpp b/Objects/private/core/module.cpp
index 3140810..91d09e2 100644
--- a/Objects/private/core/module.cpp
+++ b/Objects/private/core/module.cpp
@@ -73,7 +73,11 @@ static void deinit(const tp::ModuleManifest*) {
 	MethodObject::UnInitialize();
 
 	obj::BCgen::deinit();
+
+	assertNoLeaks();
+
 	delete NDO;
+	NDO = nullptr;
 }
 
 static tp::ModuleManifest* sModuleDependencies[] = {
diff --git a/Objects/private/core/objectsave.cpp b/Objects/private/core/objectsave.cpp
index 5da599f..adc57b4 100644
--- a/Objects/private/core/objectsave.cpp
+++ b/Objects/private/core/objectsave.cpp
@@ -3,6 +3,8 @@
 #include "NewPlacement.hpp"
 #include "core/object.h"
 
+#include "primitives/nullobject.h"
+
 #include "HeapAllocatorGlobal.hpp"
 
 #include <malloc.h>
@@ -63,6 +65,27 @@ namespace obj {
 		tp::HeapAllocGlobal::deallocate(memh);
 	}
 
+	void logTypeData(const ObjectType* type) {
+		printf("type - %s\n", type->name);
+		if (type->base) {
+			printf("Based on ");
+			logTypeData(type->base);
+		}
+	}
+
+	void assertNoLeaks() {
+		if (bottom) {
+			printf("ERROR : not all objects are destroyed\n");
+			tp::ualni idx = 0;
+			for (ObjectMemHead* memh = bottom; memh; memh = memh->up) {
+				printf(" ===== Object - %i. Ref count - %i ===== \n", idx, memh->refc);
+				logTypeData(NDO_FROM_MEMH(memh)->type);
+				idx++;
+			}
+		}
+	}
+
+
 	struct ObjectFileHead {
 		Object* load_head_adress = 0;
 		tp::halni refc = 0;
@@ -274,7 +297,13 @@ namespace obj {
 			return NULL;
 		}
 
-		setrefc(out, ofh.refc);
+		setrefc(out, 0);
+
+		// check for null object
+		if (out->type == &NullObject::TypeData) {
+			ObjectMemDeallocate(out);
+			out = NdoNull_globalInstance;
+		}
 
 		// save heap adress in "loaded_file"
 		((ObjectFileHead*) (loaded_file + file_adress))->load_head_adress = out;
@@ -405,8 +434,6 @@ namespace obj {
 		}
 		*/
 
-		setrefc(out, 0);
-
 		return out;
 	}
 
diff --git a/Objects/private/core/scriptsection.cpp b/Objects/private/core/scriptsection.cpp
index 7cf9879..930cf55 100644
--- a/Objects/private/core/scriptsection.cpp
+++ b/Objects/private/core/scriptsection.cpp
@@ -150,6 +150,8 @@ void load_constants(ScriptSection* self, ArchiverIn& file, tp::alni start_addr)
 		// script text
 		tp::alni str_addr;
 		file >> str_addr;
+
+		NDO->destroy(script->mReadable); // we already have string object in the script when creating script
 		script->mReadable = NDO_CAST(obj::StringObject, obj::NDO->load(file, str_addr));
 
 		file.setAddress(file.getAddress() + sizeof(tp::alni)); // constants length
@@ -257,6 +259,7 @@ void ScriptSection::initialize() {
 void ScriptSection::uninitialize() {
 	ASSERT(gScriptSection);
 	delete gScriptSection;
+	gScriptSection = nullptr;
 }
 
 ScriptSection* ScriptSection::globalHandle() {
diff --git a/Objects/private/primitives/classobject.cpp b/Objects/private/primitives/classobject.cpp
index 6baaf87..5131504 100644
--- a/Objects/private/primitives/classobject.cpp
+++ b/Objects/private/primitives/classobject.cpp
@@ -47,6 +47,7 @@ void ClassObject::load(ArchiverIn& file_self, ClassObject* self) {
 	alni ndo_object_adress;
 	file_self >> ndo_object_adress;
 	self->members = NDO_CAST(DictObject, NDO->load(file_self, ndo_object_adress));
+	NDO->refinc(self->members);
 }
 
 tp::Buffer<Object*> childs_retrival(ClassObject* self) {
diff --git a/Objects/private/primitives/dictobject.cpp b/Objects/private/primitives/dictobject.cpp
index 3848888..db4f6dd 100644
--- a/Objects/private/primitives/dictobject.cpp
+++ b/Objects/private/primitives/dictobject.cpp
@@ -88,7 +88,7 @@ void DictObject::load(ArchiverIn& file_self, DictObject* self) {
 		file_self >> key;
 
 		// add to dictinary
-		self->items.put(key, val);
+		self->put(key, val);
 	}
 }
 
diff --git a/Objects/private/primitives/linkobject.cpp b/Objects/private/primitives/linkobject.cpp
index 462c77b..610156e 100644
--- a/Objects/private/primitives/linkobject.cpp
+++ b/Objects/private/primitives/linkobject.cpp
@@ -49,6 +49,7 @@ void LinkObject::load(ArchiverIn& file_self, LinkObject* self) {
 	}
 	else {
 		self->link = NDO->load(file_self, saved_object_adress);
+		NDO->refinc(self->link);
 	}
 }
 
diff --git a/Objects/private/primitives/listobject.cpp b/Objects/private/primitives/listobject.cpp
index 58d7461..7d4b1d8 100644
--- a/Objects/private/primitives/listobject.cpp
+++ b/Objects/private/primitives/listobject.cpp
@@ -57,7 +57,7 @@ void ListObject::load(ArchiverIn& file_self, ListObject* self) {
 	for (alni i = 0; i < len; i++) {
 		alni ndo_object_adress;
 		file_self >> ndo_object_adress;
-		self->items.pushBack(NDO->load(file_self, ndo_object_adress));
+		self->pushBack(NDO->load(file_self, ndo_object_adress));
 	}
 }
 
diff --git a/Objects/public/core/object.h b/Objects/public/core/object.h
index 345a9e9..2a0ac05 100644
--- a/Objects/public/core/object.h
+++ b/Objects/public/core/object.h
@@ -236,6 +236,9 @@ namespace obj {
 		Object* load(ArchiverIn&, tp::alni file_adress);
 	};
 
+	void logTypeData(const ObjectType* type);
+	void assertNoLeaks();
+
 	Object* ndo_cast(const Object* in, const ObjectType* to_type);
 
 	template <typename Type>
diff --git a/Objects/tests/Tests.cpp b/Objects/tests/Tests.cpp
index 640bf29..90728d7 100644
--- a/Objects/tests/Tests.cpp
+++ b/Objects/tests/Tests.cpp
@@ -18,12 +18,19 @@ int main() {
 	tp::ModuleManifest module("ObjectsTests", nullptr, nullptr, deps);
 
 	if (module.initialize()) {
-
 		testCore();
-		testPrimitives();
-		testInterpreter();
-
 		module.deinitialize();
 	}
+
+	if (module.initialize()) {
+		testPrimitives();
+		module.deinitialize();
+	}
+
+	if (module.initialize()) {
+		testInterpreter();
+		module.deinitialize();
+	}
+
 	return 0;
 }
\ No newline at end of file
diff --git a/Objects/tests/interpreter/TestInterpreter.cpp b/Objects/tests/interpreter/TestInterpreter.cpp
index 8cb70ca..ec2ef8d 100644
--- a/Objects/tests/interpreter/TestInterpreter.cpp
+++ b/Objects/tests/interpreter/TestInterpreter.cpp
@@ -31,8 +31,8 @@ TEST_DEF_STATIC(Simple) {
 
 	interpreterLoaded->exec();
 
-	NDO->destroy(interpreter);
 	NDO->destroy(interpreterLoaded);
+	NDO->destroy(interpreter);
 }
 
 TEST_DEF(Interpreter) {
diff --git a/Strings/private/Logging.cpp b/Strings/private/Logging.cpp
index 34ec6df..4ef468d 100644
--- a/Strings/private/Logging.cpp
+++ b/Strings/private/Logging.cpp
@@ -54,5 +54,6 @@ namespace tp {
 	void Logger::deinitializeGlobal() {
 		DEBUG_ASSERT(gLogger)
 		delete gLogger;
+		gLogger = nullptr;
 	}
 }
\ No newline at end of file